Figure 1. BHPI and estrogen stimulate release of calcium from the endoplasmic reticulum into the cytosol.

A. Quantitation of intracellular IP₃ levels after 10 min treatment with DMSO, 17β-estradiol (E₂), or BHPI in PEO-4 ovarian cells (n = 3). B., C. Estrogen and BHPI increase cytosol calcium levels. Visualization of cytosolic Ca²⁺ using Fluo-4 AM; estrogen or BHPI was added to PEO-4 cells at 50 s. Color scale from basal Ca²⁺ to highest Ca²⁺: purple, blue, green, yellow, red, white. Quantitation of cytosolic Ca²⁺ levels after pre-treating PEO-4 cells with U73122, 2-APB, or Ry followed by treatment with estrogen or BHPI (n = 12-20). Concentrations: U73122, 1 μM; 2-APB, 100 μM; Ry, C8, 10 μM; E₂, 200 nM; BHPI, 10 μM. *P < 0.05, ***P < 0.001.